Self-closing cap for collapsible tubes and the like



March 20, 1956 J. M. LACHER 2,738,907

SELF-CLOSING CAP FOR COLLAPSIBLE TUBES AND THE LIKE Filed Dec. 9, 1952 F ig. 1. 4g

Z INVENTOR Ja/m M Lac/292* BY M 7 777m ATTORNEYS United States Patent SELF-CLOSING CAP FOR COLLAPSIBLE TUBES AND THE LIKE John M. Lacher, Omaha, Nebn, assignor to Lacher-Sellne, Inc., Omaha, Nebn, a corporation of Nebraska Application December 9, 1952, Serial No. 324,907

4 Claims. (Cl. 222-490) The present invention relates to improvements in caps for collapsible tubes and other containers and more particularly to a self-closing cap wherein the structure embodies means for tensioned closure of the cap opening or s it.

Closure caps of the prior art, so-called self-sealing caps, usually have a slit at the dispensing'end and an enlarged opening at the opposing end adapted to be threaded onto the end of a collapsible tube such as a tube of toothpaste, for example, the threading extending inwardly of the cap and terminating in an annular shoulder adapted to abut the end of the tube. Such caps are relatively thick so that after dispensing through the slit has terminated, the inherent resiliency of the cap will tend to return the walls of the slit to their usual relation ship and thus effect closure of the slit. Others of the prior art caps are so shaped, when molded, that they must be deformed before they can be threaded onto the end of a tube and the deformation is such as to close the slit.

As to the first mentioned type of prior art cap, it has .along the plane of line 6-6 of Fig. 5.

Referring more particularly to the drawings wherein like numerals designate like parts throughout, it will be seen that two embodiments designated generally by the numerals 10 and 12 have been shown.

The first embodiment 10 is shown in Figures 1 to 4 as being comprised of a resilient member 14 which may be molded of any suitable material. I have found, however, that plastics such as polyethylene are particularly suitable for the instant type of caps as practically all uses to which the cap can be put will result in no sticking of the material being dispensed to the cap. The member 14 is formed with a recess or pocket 16, one end portion 18, of which is substantially cylindrical and threaded and constitutes a socket for receiving the threaded end or neck 20 of the tube 22. The remaining portion of the pocket has inwardly inclined walls 24 and 26 (Fig. 3) rounded at 28 and 30 and separated by the slit 32. The portions of the walls 24 and 26 remote from the slit 32 are rounded at 34 and 36 and integrally merge with the adjacent portions of the wall defining the cylindrical socket.

been found that in molding such caps the slits also have v to be molded therein with the result that the slit has a tendency to always be parted. As to the second mentioned type, there is the difiiculty that the threading must originally be molded in the cap and be of such form that upon deformation a threaded cylindrical recess will result. Obviously, the latter procedure is difiicult of proper effectuating and poor cooperative thread association between the cap and tube results.

In view of the difiiculties heretofore encountered in prior art caps and the objections attendant thereto, it has been a primary object of the present invention to provide an improved cap that will obviate the difficulties and objections noted and which will be self closing.

A further object of the present invention has been to provide an improved cap wherein it is unnecessary to provide thick walls but on the contrary which makes possible the formation of walls of much less thickness than in prior caps.

Another object of the present invention is to provide an improved cap wherein means is embodied therein either during molding or subsequently thereto for cooperative engagement with the end of a tube so as to positively effect a tensioning along the length of the slit so as to provide for self closing upon completion of a dispensing operation.

Still another object of the present invention is to provide an improved self closing cap that will be simple in construction, facile of manufacture and effective over an extended period of usage.

Various other objects and advantages will become apparent from the detailed description to follow.

The best forms in which I have contemplated applying my invention are clearly illustrated in the accompanying drawings wherein:

Fig. 1 is an enlarged vertical sectional view along the The walls 24 and 26 are very thin whereas the portionlS is thickened for threading and provided with external ribs or flutes 38 for strength and also to facilitate gripping.

The end wall portions 40 and 42 join the wall portions 24 and 26 below the slit and are essentially triangular shaped, but form a continuation of the substantially cylindrical wall portion 18. The wall portions 40 and 42 have interiorly formed thereon means 44 and 46 (Figs. 1 and 2) which are of primary importance. The means 44 is in the form of a shoulder and is comprised of a downwardly and outwardly directed face 48, flat and somewhat inclined to the plane of the open end 50 of the cap, and a relatively curved face 52 which extends from the edge 54 of the face 48 forwardly and inwardly and merges withthe wall portion 40 short of the slit end 31 and 33. The means 46 is diametrically opposed to the means 44 and is of corresponding construction having faces 48 and 52 diverging from the edge 54 with the face 52' terminating at 33'. The faces 48 and 48' merge with the inner surface of the cylindrical wall portion 18 between them at the plane of the termination of the internal threading at 56 and 56.

From Figs. 3 and 4, it will be seen that the means 44 and 46 are elongated in a direction transversely of the slit 32 but do not encircle the interior of the cap, the shoulders terminating at 58 and 60 and 58' and 60'.

The embodiment 12 of Figs. 5 and 6 includes a cap member 62 formed of the same material as the cap 10. Instead of having ribs or flutes the cap 12 employs a turned back skirt portion 64 which encircles the cylin drical threaded portion 66 corresponding to portion 18. The upper or forward portion of the cap has inclined wall portions 68 and 70, substantially triangularly shaped wall portions 72 and 74, with the rounded portions at 76, 78, and 82, and a slit 84, corresponding to similar parts of the first embodiment. In place of the shoulders 44 and 46 of the first embodiment, there is provided a pair of diametrically opposed shoulders 86 and 88 lying substantially in line with the ends of the slit 84. The shoulder 86 is substantially triangular in cross section and rectangular in plan and includes a flat bottom face 90 coplanar with the fiat face 90' of the other shoulder and parallel to the plane of the open end of the cap at 92. The shoulder 86 has a rearwardly extending, inclined flat face 94 which extends from the edge 96 of the face 90, and terminates in juxtaposition to the end 83 of the slit 84. The shoulder 88 is of similar construction having the face 94 extending from the edge 96to the end 85 of the slit. The shoulders of this embodiment are substantially narrower than the first form and are also separately made and bonded to the interior of the cap proper after molding thereof.

In assembly, the cap of either embodiment is screwed onto the neck 20 of a container, such as the tube 22, so that the faces 48 and 48 of the first form and faces 90 and 90' of the second form abut the end face 98 of the neck end. A slight further turning is effected so that the shoulders exert outward forces against the triangular wall portions 40 and 42 in the first form and 72 and 74 in the second form, thereby tending to exert expanding force at the ends of the slit in a direction longitudinally of the slit, the tensioning along the slit forcing theslit to tightly close.

In dispensing, the tube contents is forced out by squeezing the tube and the pressure of the contents will overcome the above referred to tensioning so as to pass outthe slit. When the squeezing of the tube ceases, the tensioning along the length of the slit goes into effect to close the slit and prevent further dispensing.

.If desired, after extended usage, the cap can be further tightened upon the neck 20 to compensate for loss in tension due to fatigue.

Of course the shoulders of either embodiment could be molded with the cap proper or separately made and thereafter assembled. Furthermore, the shoulders could be made of a material different from that of which the cap proper is made.

As shown, the slit extends diametrically of the cap but it will be understood that other arrangements are contemplated.

From the foregoing, it is thought that I have provided improved self-closing caps for collapsible tubes that will accomplish all of the objects hereinbefore set forth.

The wall portions 24, 26, 68, 70, 72 and 74 have a thickness of .020 inch at their thin portions. This thickness may be varied according to both the size of the cap and the material to be dispensed. The threaded portion of the cap shall be approximately twice the thickness of the other walls.

The exterior of the threaded portion, including the ribbed exterior at 38 and the turned back portion at 64, can be varied. For example, the ribs 38 and portion 64 can be eliminated and the exterior of the threaded portion left smooth or milled.

I claim:

1. A self-closing cap for collapsible tubes and other dispensing containers having a threaded discharge neck, said cap comprising a hollow body of resilient material having an open rear end internally threaded and across its front end having a transverse outlet slit normally closed, inwardly projecting shoulders spaced from each other circumferentially of the body and located at opposite sides of said body between the threaded open end portion thereof and opposite ends of the outlet slit having rear ends overlapping said neck, and portions of walls of the body between said shoulders extending upwardly at an inward incline towards opposite sides of the slit, said shoulders being pressed upwardly at an outward incline by the overlapped upper end of the neck when the cap is tightened thereon and thereby exerting pull in opposite directions longitudinally of the slit at opposite ends thereof and urging side walls of the slit towards each other to close the slit.

2. The structure of claim 1 wherein the shoulders have flatneck-engaging surfaces at their lower ends disposed at an abrupt angle to the threaded portion of the body, said shoulders being reduced in Width and thickness towards their upper ends and having surfaces disposed at an outward incline towards their upper ends whereby upward pressure against the lower ends of the shoulders will be exerted outwardly against portions of the body at opposite ends of the slit.

3. The structure of claim 1 wherein the wall portions abovethe threaded portion and between the shoulders are of'reduced thickness and the inwardly projecting shoulders are integral with walls of the body.

4. The structure of claim 1 wherein the wall portions above the threaded portion and between the shoulders are of reduced thickness, the shoulders consisting of blocks extending longitudinally of the body and being of a width greater than the width of the slit and extending beyond opposite sides thereof.

Smith Dec. 25, 1928 Duey July 9, 1940 

